BUILDERA Crack Monitor Installation INSTRUCTIONS | CRACKMON® 4020A


Thank you for purchasing BUILDERA™ CRACKMON® structural crack monitors, the engineer’s choice™. BUILDERA designs and manufactures the CRACKMON 4020A in the USA, providing years of reliable indoor and outdoor endurance. Follow this installation guide and all safety precautions to ensure a fail-proof installation. Always wear eye protection and gloves when using power tools and structural adhesives.


Structural Epoxy (Method 1)

  1. If surface is damp, allow to thoroughly dry, or use Method 2.

  2. Remove and clean loose debris from crack using stiff bristle or wire brush.

  3. Thoroughly mix Buildera STRUPOXY™ thixotropic epoxy adhesive (Aboweld™ 8101-5) following package directions.

  4. Apply thick 3-4 mm layer of epoxy to backside of both CRACKMON mounting tabs in the vicinity of holes (2x3 cm area). Rough or uneven mounting surfaces may require a thicker application.

  5. Center red crosshair on grid and over crack. Press CRACKMON firmly into place across crack at 1-m (3-ft) typical unit-to-unit spacing. Epoxy should fill holes. Level and adjust to ensure accurate grid alignment prior to initial setup. Hold in place for approximately five (5) minutes until initial bond sets.

  6. Secure CRACKMON in place with duct tape for 24 hours until epoxy cures. After cure, remove duct tape. Score clear tape on top and bottom edges with a sharp knife or razor blade. Remove residual clear tape from CRACKMON to allow free motion.

  7. Note X-Y start position on TRACARD® 3D or crack-progress sheet. Inspect movement periodically. Document with phone/camera and CRACKMON 224R Crack Comparator (ACI compliant).

Anchor & Fastener (Method 2)

  1. Remove and clean loose debris from crack using stiff bristle or wire brush.

  2. Adhere CRACKMON 4020-TMP drilling template over crack (included with recommended mounting kit UPC 816291010242, sold separately).

  3. Bore four 1-1/2” (4 cm) deep holes using a cordless hammer drill and 3/16” (ø5 mm) concrete bit. Blow out debris from hole. Use eye protection!

  4. Insert one 3/16” (ø5 mm) A5 Toggler® Alligator® anchor into each hole. Tap flush with a hammer. For best results, do not use any other anchor.

  5. Fasten CRACKMON with four #6 or #8 x 1-1/2” stainless-steel sheet-metal screws and lock washers. Tighten last turns by hand. Over-torquing screws may inadvertently damage the gauge or shear o the screw head.

  6. Score clear tape on top and bottom edges with a sharp knife or razor blade. Remove residual clear tape from CRACKMON to allow free motion.

  7. Note X-Y start position on TRACARD® 3D or crack-progress sheet. Inspect movement periodically. Document with phone/camera and CRACKMON® 224R Crack Comparator (ACI compliant).

  8. Mount with tamper-resistant screws and epoxy for best results and security.